Aggression will also define the 'risk takers', so in itself is not a bad thing. Discipline is more important, and especially in the back row. In some ways a perfect back row forward is Psychotic aggression with Flawless discipline, meaning they will go for the ball in a controlled manner, thus meaning a better chance of a turnover.

If you do have to play a back rower with Reckless or Rebellious discipline, it is worth considering playing By The Book in the tactics